1. Field of the Invention
The present invention relates to a sheet storing apparatus which stores sheets fed from an image forming apparatus or the like at a downstream stack tray with or without performing a post-process thereon, and relates to improvement of a sheet discharging mechanism which conveys a sheet fed from a sheet discharging path toward the downstream stack tray.
2. Description of Related Arts
In general, in such a sheet storing apparatus, a pair of frictional rotors are arranged at a sheet discharging port and sheets are conveyed to the downstream side thereby. Belts, rollers, or the like have been adopted as the frictional rotors. For example, Japanese Patent Application Laid-Open No. 2009-035371 (Patent Document 1) discloses an apparatus in which a sheet fed to a sheet discharging path is conveyed by a pair of rollers arranged at a sheet discharging port selectively to a processing tray or a stack tray at the downstream side. The processing tray is provided with a post-processing mechanism such as stapling mechanism to perform staple-binding as collating and stacking sheets fed from the sheet discharging path and to discharge the bound sheet bundle to the stack tray.
The sheet discharging path is arranged so that sheet conveying to the processing tray and sheet conveying to the stack tray can be selectively performed. In the apparatus of Patent Document 1, a sheet at the sheet discharging port is fed to the stack tray when the pair of sheet discharging rollers arranged at the sheet discharging port are rotated in a forward direction and is fed to the processing tray when the rotation thereof is switched from the forward direction to the reverse direction.
In Patent Document 1, a reversing roller is connected to a drive motor as being rotatable in the forward and reverse directions and the pair of rollers are arranged as being switchable between an operation state of being mutually press-contacted and a waiting state of being separated. In the above structure, a roller (upper roller) to be engaged with an upper face of a sheet fed from the sheet discharging port is supported by a swingable arm member and the arm member is connected to an actuator such as a motor and a solenoid. A detection signal from a sheet sensor arranged at the discharging port causes the upper roller to be vertically moved from the waiting position being apart from the lower roller to the operation position being pressure-contacted thereto.
Further, Japanese Patent No. 4057233 (Patent Document 2) discloses a sheet discharging mechanism with discharges sheets by a pair of rollers through a sheet discharging port. Here, Patent Document 2 discloses the pair of rollers which are mutually pressure-contacted and a paddle member which is arranged around the pair of rollers. With the sheet discharging mechanism, a sheet is discharged through the sheet discharging port by the pair of rollers and a sheet tailing end being apart from the rollers is kicked by the paddle member to prevent the sheet tailing end from being jammed as being caught on a roller circumferential face after leaving from the rollers.